1. Field of the Invention
The present invention relates to a ball and socket trailer hitch with a throat that is capable of automatically seating and locking a telescoping member capable of lateral swinging movement. The hitch allows a stationary towing vehicle having been imprecisely aligned with a stationary trailer to be coupled without realigning either the trailer or towing vehicle, and then in one backing motion of the towing vehicle, automatically aligning and locking the hitch into a towing configuration.
2. Description of the Prior Art
Conventional ball and socket type trailer hitches are in common use for towing trailers behind passenger and light utility vehicles. However, the ability of a driver to back a towing vehicle trailer and align its hitch with a stationary trailer, so that the socket in the tongue of the trailer and the ball of the hitch align, approaches an art form. This ability is particularly desirable when the towing vehicle is operating under tight-radius circumstances or when no other person is available to direct the backing procedure.
The procedure of coupling a trailer and a towing vehicle typically requires that the towing vehicle be moved into close proximity with the trailer tongue so that the tongue of the trailer can be lowered down upon the ball of the hitch. Once the hitch is properly positioned, the socket of the tongue is lowered down upon the ball, secured and locked into a towing configuration. Numerous inventions can be found prior art using various structures in order to overcome the problems of aligning and locking the hitch assembly into place.
For example, U.S. Pat. No. 5,322,315 issued Jun. 21, 1994 to Carsten describes a towing hitch having a body with a pocket within which a receiver tube is permanently pivoted by a trunnion allowing an arcuate movement of the receiver bar in a 60 degree arc bounded by the pocket's walls. The receiver tube is also capable of telescopingly capturing a tow bar (on which a coupling ball is mounted). The hitch is locked into a towing position using two pin assemblies. This must be accomplished by a forward and backward movement of the towing vehicle relative to the trailer. When the towing vehicle pulls forward, the angle having been formed by the trailer and the towing vehicle decreases until the towing vehicle and trailer are in alignment at a zero angle. A first pin assembly then automatically locks the receiver tube to the body by engaging with a recess fixed in the body at the zero angle. A second pin assembly automatically is capable of locking the tow bar within the receiving tube. However, the tow bar is shown to extend in a direction only along the radius in which the receiving bar is positioned. Therefore, in order to retract the tow bar from an extended position, the vehicle must be first pulled forward to lock the first pin assembly, then backed straight back to retract the tow bar until the second pin assembly locks. Although the telescoping and laterally swinging nature of the device allows the towing vehicle and trailer to be coupled while only being moved into a close proximity, a great disadvantage of this system is that the vehicle must be maneuvered forward and back at least once before a safe towing configuration is achieved. Furthermore, any misalignment of the towing bar within the receiving tube may cause the bar to remain extended during the backing phase of the locking procedure.
U.S. Pat. No. 4,792,151 issued Dec. 20, 1988 to Feld also describes a self-aligning, self-locking and self-leveling trailer hitch, which requires that a first assembly (a double-ended ball) be manually and securely fitted into the socket of the trailer. The towing vehicle is fitted with a second assembly, a downwardly sloping and outwardly flaring ramp with self-locking, interfitting dual-jaws, which jaws when closed receive the first assembly. The flared portion of the ramp must be backed into contact with the first assembly so that, while the towing vehicle continues to be backed, the first assembly is forced to travel up the incline into the jaws. A great disadvantage of this invention is that the towing vehicle must still be backed with near precision to bring the tongue of the trailer and the hitch into contact.
U.S. Pat. No. 4,073,508 issued Feb. 14, 1978 to George et al. describes an adjustable ball and socket type trailer hitch with a rotatable, extensible and hinged arm adapted to pivot on, extend from, and retract into a housing. The hitch is characterized by a folding outer and inner arm capable of extending from and folding into a housing whereby the ball of the hitch can be maneuvered into substantially any position within the range of the extended outer arm after the towing vehicle is backed into close proximity to a trailer.
U.S. Pat. No. 4,807,899 issued Feb. 28, 1989 to Belcher describes a hitch with a winch, retractable cable and tubular receiving passage into which a tapered hitch bar is drawn in order to align the trailer and hitch. A plunger locking pin is used to secure the hitch bar and receiving passage to engage a towing configuration. U.S. Pat. No. 5,288,095 issued Feb. 22, 1994 to Swindall describes a simple device which is bolted by a base plate to the bumper of a towing vehicle. A tubular housing is attached to a base plate through a trunnion to permit arcuate movement. A slide bar with a ball is telescopingly captured by the housing in the same radius as the position of the housing. A spring loaded locking pin secures the slide bar in place.
Devices directed to applications which allow a trailer tongue to telescope and swivel, as contrasted to applications directed at the towing vehicle hitch, are also found in the prior art. U.S. Pat. No. 5,277,447 issued Jan. 11, 1994 to Blaser describes a retro-fit adaptor for use with commonly used two-part trailer hitches. The adaptor can be either interposed between and attached to a ball-supporting member and a supporting guide tube attached to the towing vehicle, or, interposed between and attached to the socket-supporting member and a supporting guide tube attached to the trailer. The adaptor is capable of both axial and lateral swinging movement for coupling of vehicles. The adaptor has angled faces which cam the supporting member and supporting guide tube into alignment as the towing vehicle is backed towards the trailer.
U.S. Pat. No. 5,213,354 issued May 2, 1993 to Vaughn is directed in application to a trailer and describes a tubular draw bar which is guided within walls of an elongate base member by a rolling pin. The base member is affixed to a triangular frame plate forming a part of the trailer.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.